Topic: 78 CB750K HIGH SPEED PROBLEMS

[ocroble]

I JUST BOUGHT MY 78 ABOUT A MONTH AGO FROM A LOCAL SHOP. IT'S BEEN RUNNING ALMOST PERFECT EXCEPT OCCASIONALLY AT HIGH SPEEDS IT WOULD KINDA BACKFIRE EVERY NOW AN THEN.

IVE BEEN DOING MORE HIGHWAY RIDING AND A COUPLE OF DAYS AGO IT JUST STARTED DECELERATING SO I PUT IT IN FOURTH GEAR AND TRIED TO ACCELERATE BUT NO RESPONSE...
SO I JUMP ON THE ACCESS ROAD AND IT KEPT DOING THE SAME THING FOR A COUPLE MILES AND THEN RETURNED TO NORMAL.

IT SEEMS TO ONLY DO THIS AFTER HITTING A HIGH SPEED FOR A WHILE AND MAYBE LIKE ITS NOT GETTING FUEL AT THESE TIMES.

THIS IS MY FIRST BIKE AND I REALLY DON'T KNOW MUCH ABOUT EM.

WAS HOPIN SOMEONE MORE KNOWLEDGEABLE COULD GIVE SOME SORT OF CLUE AS TO WHATS WRONG.

[BobbyR]

I have the same bike and it acts like that when I need to switch to reserve. Check to see if your tank screen is clean. Also if you have an inline filter it may be clogged. You can also check you float bowl level. It is easy. Get a piece of clear tubing and connect it to the drain at the bottom, hold the open end up higher than the float bowl so you don't spill gas. Open the drain and see what level the gas rises to when you place the tube against the bowl. This way you can see the level without having to remove the bowl.

[shoemanII]

if this happens again, pull over and remove the gas cap.  if you hear a "whoosh" or "hiss", your tank vent is blocked.  you need a tank vent so your bike gets free-flowing fuel.
bobp

[eldar]

When I had this, it was either needing to switch to reserve or I had a small piece of crud in the carbs. When that happened, I pulled the choke and gunned it and it would sputter but then I let off and it blew out whatever was blocking things.

[BobbyR]

Bob W has it right whan he says. CARBS SUCK.

[eldar]

No FOUR carbs SUCk!

[goon 1492]

They said it all, even the sucky part  . Mine does the same thing after a few minutes when I shut the fuel off about a block or two away from home, this was when I didn't have it in pieces though......

[BobbyR]

I guess when you look at all the comments everyone feels it is fuel starvation related. It could be a simple or not so simple fix.